Hello. I have sewage cleaning equipment powered by a cat 3306 engine. The problem is that the engine oil (fuel gets in) after 10-15 hours of operation, about 10 liters. Fuel injections are new, the fuel pump is repaired, new sections and seals. I also assumed another used one and it is the same. Pre-pump replaced by electric. (0,2 bar) The engine does not smoke, there are no blows to the engine after firing, it works evenly, has power. Where can the fuel get? Has anyone had a similar problem and has it been fixed?
What's the s/n of the engine? Have you checked transfer pump seals?
Yes. everything is new. pump is after rebuilt. unless the company did it wrong ... because it is not very possible that fuel could be refilled by other means. There are similar threads on various forums, but no one wrote how it was fixed and what was the reason why the fuel got into the oil. Engine 3306 engine model 64z28161 number 1312991 here, for example, there is a similar option but it is not written how it worked Caterpillar Forum - 3306 fuel in oil (2958) on 2008-06-10 (dieselenginetrader.com) please help
No mechanical transfer pump. Retrofitted with electric. A rebuilt injection pump. Reman nozzles. It probably has a leaking fuel nozzle with a case of post-nasal drip. It’s not uncommon to have issues with new or reman nozzles. Tell us where the parts came from. Genuine Cat or from the Dollar Store?
the nozzles are new, non-original replacements. apart from injections and an injection pump, is there any possibility that you get fuel into the oil? pump was regenerated by a local company with experience. In Poland there is a problem with the repair of caterpillar 3306 because it is not enough.
No other possibility. If it was my job, I would pull and test the nozzles. Easy to test with a basic nozzle tester. Might be obvious like a blown nozzle tip. Those are amazing engines and will run fairly well even with significant problems.
thank you so we will. I will write how I can solve the problem
one more question buddy. I have 8N7005 injectors, are these the correct injectors for my engine model? in the company I was buying, they came out of the catalog and I would like to be sure if there is any mistake here.
and if I remove the injectors, does it make sense to measure the compression pressure of the engine?
I show an as shipped part number of 100-7559 with a reman number of 0R-4340 fuel nozzle assembly. No idea what the difference is in them but they are different in some way.
George, Hello. I’m sorry. I have no way to look that up for you at the moment. How’s it running? Lots of black smoke? I wouldn’t spend the time on a compression test. Well, at least until you are convinced the nozzles are good.
Lot of suggestions been put up but a few pictures of the engine might help more, I see the 64Z tag but again a picture would help a great amount, if it is a D.I engine i would guess it to be a 3306 -2 with the large type fuel pump that has a low pressure lift pump fitted, and by your script it would sound to be by-passed?? this pump is the usual culprit to cause fuel in the oil, I will warn you that anything around a 5 to 10 liter dilution in the engine oil will take out the main bearings fast, the big end bearings will be fine but the rotating mass of the crank and rods will spin the main bearings in the block, if an injector is dropping fuel into the cylinder then I would expect to have a hydraulic lock effect on the faulty cylinder plus white smoke clouds if it ever ran, so that brings things back to the injector pump, how do you want to play it? tctractors p.s. with this amount of fuel dilution the main bearings must be near scrap, the engine will run strong with just the slight stink of fuel but i would be checking the crank.
That's going to be a late s/n 3306B. With the transfer/lift pump by-passed there are only two other sources for fuel in the oil. Either an injector problem which seems unlikely the way you describe it runs or the governor which is a hydraulic servo type using engine oil pressure. I don't know for sure but it may be possible to back feed fuel through the servo into the engine oil system. Need some more expertise here as this is much to new for me.
Is the lift pump completely bypassed or did you just put an electric pump in line?
You nailed it, Old Magnet. Nothing else it can be.
Each pump element sits on a ground and lapped spacer, circled in red. If they haven't been installed correctly, fuel will leak past here.
Wise words. I stress every time I change a p&b in the mud & blood. Been fortunate over the years.
Yes. it is omitted the mechanical pump only uses electric. That one is blinded
,,Hello. I’m sorry. I have no way to look that up for you at the moment. How’s it running? Lots of black smoke? I wouldn’t spend the time on a compression test. Well, at least until you are convinced the nozzles are good.'' it does not emit black smoke or any other. it's ok. I have to work on this equipment because I have a contract with the company and no other option. I change the oil every day or every 2 days. I hope the engine will survive it ... because in all of POLAND I found only one engine used with 6000mth. If I can't fix it, then I go in that direction.
In your description early on you indicated you tried another (complete?) injection pump and got the same results. If that's the case it would seem that fuel injection issues would be the last possible cause. As was previously mentioned it would be best to get those injectors tested or replaced. At least that would eliminate one of the possible causes. If you replace them get the right ones which appear to be part number 1007559.
Me and my 80 year old brain have been thinking about your fuel contamination dilemma. It just occurred to me that what would be an obvious leak with old school stand alone injectors would not be so obvious when connections are buried under the valve cover. What I am referring to is on a somewhat rare occasion an injection line ferrule may have split or otherwise not seal. To check it out: 1. Loosen the line nuts at the injection pumps one at a time with engine running to kill the injection pressure and see if at least one cylinder is loafing and not carrying the load. 2. Pull the valve cover and run engine while looking for a leaking line connection at the injector. 3. If you want to get fancy try the dye and light check like shown in the attached video. Seems this would fill the criteria for the symptoms you've given. Please let us know if you've done this already or how it works out. Good luck.
I was going to suggest exactly what cmark did. Other than that. Dye the fuel and get a black light
interesting video, I appear to have diesel in my oil, but the injectors are not under the rocker cover. So the injector I assume in this case can not be the diesel in oil problem.
Well, there goes that theory..... I still see where the Cat SIS trouble shooting for fuel in oil states injectors as a source. If not injectors it's back to the injection pump. About the only way I can see fuel getting into the oil is past the pumps. Rare to happen but seats can go bad with loss of sealing, housings can crack or distort. Unfortunately governor oil drain back and pump drain flow is to inaccessible areas where leak check is not possible on the engine. Leakage check would have to be done on the test stand. Also doesn't explain why changing the complete pump and governor unit still had the same results. If it's of any use governor drain is down through the support bracket and pump drain is out through the engine timing gears. I'm out of ideas.
injectors ordered. will be on 6.06 for collection, we will assume and see if it is ok
number 1007559.
Be a good idea to do do my recommendation #1 anyway to check if one or more cylinders are having a problem.
what do you mean that 1 of the cylinders you mean the injector or the pressure (rings, piston, sleeve?)
I was thinking injector but the check could indicate a weak cylinder for other reasons. If the injector was over fueling I'd expect smoke....which you don't appear to have. The 3306B injector pumps have a residual check valve that normally maintains 1000 psi in the line. Plenty of time for leakage if the injectors are faulty but again where's the smoke!!!! New injectors may not be the answer but at least that will eliminate one possible cause. Are you getting any help/advise from the shop that rebuilt your injection pump? You mentioned having an identical pump. Would it be possible to get that pump on a test stand for a more thorough check?
it is now being checked, I have to pick it up in a week, but first I will replace the injectors and we'll let you know it will work
Here's some info on governor and pump lube oil flow. Would have to be duplicated on the test stand. Have them dye and check output oil flow for fuel, especially the pump section.
Any news of progress?
Buddy, the delayed delivery of the injectors will only be around 20.06 or a few days later, I will definitely write what happens after the replacement. I picked up the second injection pump today which was in check and it turns out to be good. So only the injectors or the engine pressure that I am going to measure when replacing the injectors remain.
Hello. I installed the correct injectors and the oil in the fuel stopped coming, but I also measured the engine pressure and on 5 cylinders it is 26 bar and on 1 only 15 (the first from the gearbox side) I also did an oil test (I poured the oil into the cylinder and we measured the cylinder pressure again. has not increased) so probably one of the valves will be damaged and I will have to take care of it in the near future.
Well, that's mostly good news. Thanks for the follow up info. Could be a ring problem with that one cylinder. If the injector in that cylinder was over fueling it would wash away the lubrication of the rings resulting in excessive ring wear and glazing of the cylinder liner.